.input-group {
    width: 500px;
    margin-left: 40%;
}

.input-group-addon {
    width: 40px;
}

.input-group * {
    height: 50px;
}

.btn-group {
    margin-left: 40%;
}

.alert {
    margin-left: 40%;
    width: 500px;
    display: none;
}